The families of the victims on the Germanwings plane, which was deliberately crashed into the French Alps by co-pilot Andreas Lubitz, are suing the flight school in the US where he underwent training.

The suit claims that the school failed to properly screen his medical background.

The case was filed in the US District Court in Phoenix against the Airline Training Centre of Arizona which is owned by Lufthansa, the parent company of Germanwings.

While training in Europe with Lufthansa, Lubitz had been suspended from his academic course work for nearly ten months while he sought treatment for depression.

In 2010, after returning to Lufthansa, he was sent to Arizona for flight training.

The suit, on behalf of 80 families, alleges that if the school screened Lubitz before offering him training, it would have discovered that he'd been previously been in hospital for severe depression and treated with medications that would have prohibited him from flying.

In March last year, Lubitz deliberately steered the Germanwings flight into the mountains after locking the pilot out of the cockpit.

All 150 people aboard, including Lubitz, were killed.